1. Field of the Invention
The present invention relates to a tool that allows seedling to grow in a short period, a system for growth with the use of the tool, and a method for growth. More specifically, the present invention relates to a tool for promoting growth, a system for promoting growth with the use thereof, a method for promoting growth, and a plant for promoting growth that allows seedlings to grow smoothly in a short period even in areas difficult to raise plants as planting ground, for example, dry land, cold desert where the surface layer of the soil is frozen, and salt accumulation area where salt is accumulated in the surface layer of the soil, and further to seedling set for planting and a method for planting seedling.
2. Description of the Related Art
As is well known, the moisture content in the ground in dry land is very low compared with that in other areas easy for greening. The result obtained by measuring the moisture content in the soil with respect to soil depths in Nigeria in Africa in 2000 is shown in FIG. 19. For example, in the land involved, as shown in the figure, the moisture content is little in the soil surface compared with that in the soil equal to or deeper than 30 centimeters where a relatively stable moisture content is found. Accordingly, survival of plants in dry land depends whether roots can reach a deep layer with this stable moisture fast enough.
In salt accumulated soil widely distributed in the world, salt is often contained in a large amount in relatively shallow part (20 centimeters or 30 centimeters deep from the like, there are further points of improvement in respect that water is lost due to evaporation, even though its amount is small, and so forth.
Even in the measures for greening of dry land with the use of plant species having salt resistance, the possibility that organic damage may occur is high and the establishment in the land is difficult in reality even though a plant species having salt resistance is used because of an excessively high salt concentration.
The method for removing salt in soil by washing that is used when there is a rich water source nearby is unrealistic because such a water source cannot be secured in dry land.
In pot culture and open culture that are used as a method for preparation of a seedling used for planting, the time period of raising the seedling is long. On the other hand, when a huge quantity of seedlings can be raised in a short period, this technology can be expected to enhance water conservation and production quantity of seedlings and is very useful for greening project in dry land and cultivation of other plants, vegetables, and the like.